1. Field of the Invention
The invention concerns a mobile concrete pump with at least one front axle and at least one rear axle associated with a chassis, with a rotation gear for the distribution boom provided on the chassis near the front axle, with a pump assembly mounted on the chassis and separated from the rotation gear in the direction of the rear axle by a free space, with a vehicle chassis support structure which comprises two curved telescopic guides fixed to the chassis into which two curved support struts can be retracted and from which they can also be diagonally extended towards the front, wherein the telescopic guides extend in horizontal planes in an area between the two longitudinal sides of the chassis and exhibit geometric curvatures about respective center points, which center points are distanced sideways from the longitudinal side edges outside of the vehicle chassis and mirror symmetric to the vehicle chassis.
2. Description of the Related Art
A mobile concrete pump of this type is known (EP-B-661196), wherein the telescopic guides extend respectively from one of the longitudinal side edges of the chassis towards inwards essentially to the vehicle center, and from there to the same longitudinal side edge, whereby the vehicle longitudinal axis runs tangential to the guides. The geometric center the curvature (center of a circle described by the arc) herein lies mirror symmetric to the vehicle longitudinal axis, distanced sideways from the longitudinal side edges outside of the vehicle chassis, and mainly forwards (in the vehicle driving direction) of an imaginary connecting line extending between the rearward ends of the telescopic guides. For this telescopic guide, less than one half of the vehicle breadth is available. The exit side tangential angle of the telescopic guides is correspondingly small in comparison to the adjacent longitudinal side edges. In practically realized cases it corresponds to less than 40xc2x0. In order to nevertheless achieve a sufficient stance or setup breadth, relatively small curvature radiuses are required in the support struts, which typically lie within the 1.6 to 1.8 multiple of the vehicle chassis breadth. These relatively small curvature radiuses limit the maximal possible extension width to a relatively small value. On the other hand, the high torsional load of the support struts in this case require a stiffening or rigidifying with great investment in material.
Beginning therewith, it is the task of the present invention to improve the known mobile concrete pumps with telescopic support struts of the above described type in such a manner that with a given vehicle chassis breadth a large support width can be achieved with simple means.
The inventive solution uses the entire vehicle chassis breadth for the storage or mounting of the telescopic guides. Only therewith does it become possible to increase the curvature radius in the support struts, and therewith to achieve suitably large support breadths even for large distribution booms. In order to accomplish this it is proposed in accordance with the invention that the two telescopic guides cross in different planes in the area of the rotation gear, or in the free space between the rotation gear and the concrete pump, and that the geometric curvature center point of the telescopic guides (center of circle described by arc of telescopic guides) is aft of an imaginary connecting line extending between the rearward ends of the telescopic guides. The curvature radius of the telescopic guides achievable therewith is larger than two times the vehicle chassis breadth. Preferably, the relationship of radius of curvature to vehicle chassis breadth is between 2.2 and 3.2. It is further of advantage when the telescopic guides on the exit side in the area of the longitudinal side edges enclose a tangential angle with respect to the adjacent longitudinal side edge of 40xc2x0 to 70xc2x0.
Preferably the tangential angle of the exit side lies between 45xc2x0 and 60xc2x0. At their rearward ends the telescopic guides preferably form with the adjacent longitudinal side edge a tangential angle of 1xc2x0 to 25xc2x0. The preferred rearward tangential angle lies in the range between 2.5xc2x0 and 20xc2x0.
The additionally required rearward support struts are preferably formed as pivot struts, which are pivotably connected rearward of the telescopic guides. In place of pivot struts it is however also possible to use telescopic support struts arranged or provided transverse or diagonal to the vehicle chassis longitudinal axis.